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View Full Version : HD-DVD/BluRay & SDI - how do they all fit together?


Sniper
08-03-2006, 10:15 AM
I have no particular experience on the SDI matter, but would there be any obvious reasons to go that route with HD players?
If I'm not mistaken the HD players use mpeg4, rather than mpeg2, will that be of any concern?
Can SDI be affected by HDCP? / Can HDCP be 'affected' by SDI?

Sorry for any silly questions!

JohnWH
08-03-2006, 12:00 PM
In theory there is no SDI for HD DVD or blueray, you have to use HDMI/DVI+HDCP, and in theory the players are not allowed to have an unencrypted tap off point external to the chip (someone mentioned elsewhere that his was in top and bottom PCB layers only) so mods may be unlikely.

John.

KraGorn
09-03-2006, 10:11 AM
Per se, SDI and HDCP aren't related .. SDI is an electronic interconnection while HDCP is data encryption. In principle there's nothing stopping the extraction of the raw decoded signal as long as its' still infested with HDCP, thus achieving SDI(HDCP), however AFAIK there's no practical purpose in doing that and so no-one is planning to do it.

That said, as John said, SDI-ing a player in the way it's done in SD land would be in breach of the HDMI/AACS/whatever license and no doubt will be descended upon from great heights by herds of lawyers to nip it in the bud.

welwynnick
09-03-2006, 10:38 AM
AIUI, Pixel Magic Systems are developing an HD-SDI mod kit for use on BD & HD-DVD players (and maybe other HD sources). That would take the decoded and up-sampled 720p and 1080i YCbCr 4:2:2 digital video signal directly from the output of the MPEG 4 (and 2) decoder, and feed a Crystallio 2 or Vantage etc scaler in the same manner that SD-SDi does today.

Because all the MPEG4 storage is kept on the disc side of the MPEG decoder, it doesn't matter whether the BD or DVD is encoded in MPEG 2 or 4 - SDI has no knowledge of that, it is just a digital component interface. HDCP is also irrelevant, because the encryption is applied later by the player.

HOWEVER, as mentioned Blu-ray etc players may not have the same access to decoder output pins as DVD players, and the decoder may do other video processing (like the current Sky+ box) so there may be no unprocessed video output. In addition, that output would be at a much higher data rate than even frm DVDs - about five times higher. So all the installation problems associated with high frequencies that people have been having with SD-SDI installations will be greatly magnified.

I live in hope, but HD-SDI may be a lot to hope for.

Nick